Communication networks are comprised of heterogeneous network elements (NE) such as telecommunication terminals, switches, routers, amplifiers, etc. interconnected in various configurations by physical hardware connections, and the software used to send, receive and route the information between these NEs. Network elements are each a complex programmable system, including programmable subsystems and local memory for storing the respective programs and maintaining records of the operating history.
The current trend to integrate smaller networks of various technologies into global networks that extend over tens of thousands of miles, demands reliable and sophisticated tools for monitoring and controlling operation of a very large number of network elements, which are spread over a large geographical area. In addition to the challenge posed by the size of the network, topology of a telecommunications network is continually changing as equipment is added, removed, relocated and/or upgraded. Still further, network customers demand fast response to any service request: a corporate user of bandwidth which requests additional capacity will be severely hampered if the response is not prompt.
Driven by the need to develop and deploy highly scalable new services in a rapid and cost-effective manner, the network management systems (NMS) are rapidly evolving towards highly distributed, multi-vendor systems with open interfaces that enable applications that are independent from the underlying transport technologies. A NMS receives real time information about status, operation and performance of the NEs and systemizes this knowledge such that communication problems can be detected, isolated and corrected, either automatically or by the maintenance personnel. A NMS is provided with a graphical user interface (GUI) that enables an operator to input commands and to interact with various network entities.
The NMS maintains a network map (also known as network view or network topology view) with hierarchical information about network topology, i.e. the equipment and connectivity data. Such maps show the NE location in the network indicating the node of residency, and eventually a node group to which the node belongs. A node group is a logical grouping of nodes and NE's, and may also include other node groups. This topological information changes due to network configuration changes; whenever the network topology changes, the NMS map must be modified accordingly to accommodate this change.
To keep pace with the ever-increasing size of networks, a NMS communicates with a plurality of element management systems (EMS). An EMS is similar in role to the NMS, except that it manages NE of a specific type, from a specific network provider or vendor. EMS's also have an important role in configuring, provisioning, operating and monitoring the network elements they manage.
An EMS may also maintain a map with hierarchical information about the topology of the sub-network it controls. As the number of EMS's in a network increases, it is a challenge to keep the NMS and EMS's in synchronization regarding the network topology.
In general, the alignment between the EMS and NMS maps is performed manually. This is however extremely time-consuming and cumbersome, not to mention error-prone for even the smallest changes or reorganizations in the hierarchy, or the naming of the node groups in the hierarchy. For example, if each node's location in the node hierarchy on the NMS map is used to generate the location identifier of that node on the EMS map, then changing a group name is a complex task because a group may include dozen of network elements, and the name change requires changing the EMS location identifier of each NE in the group.
Map alignment is particularly challenging for EMS's that manage subscriber access systems; such an EMS can manage hundreds of subscriber access multiplexers (SAM). A SAM multiplexes the data received from the user ports into the network. Return data from the network is demultiplexed by the SAM for communication to the clients via the respective ports. The SAM also enables scaling-up the number of users by gradually populating unused ports. As an example, a DSL (digital subscriber line) communication network uses a DSL access multiplexer (DSLAM), which is typically located at a central office of the telephone network and includes multiple DSL modem ports for connecting multiple client modems.
U.S. Patent Application 2003/0140132 A1 (Champagne et al.) published on Jul. 24, 2003 describes a method of updating network device information and synchronizing the NMS database with the configuration information maintained at a network device. The synchronization process can be initiated in the NMS in response to input from a network management client, and can also be initiated via a message from the network device at power-up or upon insertion or removal of a circuit card. As a result, the NMS sends an upload configuration request to the network device, and the network device responds by transferring a configuration file containing the current configuration information. However, this patent application does not disclose synchronization of NMS and EMS network views.